What Eating Too Much Sugar Does to Your Brain

Overeating, poor memory formation, learning disorders, depression—all have been linked in recent research to the over-consumption of sugar. And these linkages point to a problem that is only beginning to be better understood: what our chronic intake of added sugar is doing to our brains.

According to the U.S. Department of Agriculture (USDA), the average American consumes 156 pounds of added sugar per year. That's five grocery store shelves loaded with 30 or so one pound bags of sugar each. If you find that hard to believe, that's probably because sugar is so ubiquitous in our diets that most of us have no idea how much we're consuming. The Centers for Disease Control (CDC) puts the amount at 27.5 teaspoons of sugar a day per capita, which translates to 440 calories—nearly one quarter of a typical 2000 calorie a day diet.

The key word in all of the stats is "added." While a healthy diet would contain a significant amount of naturally occurring sugar (in fruits and grains, for example), the problem is that we're chronically consuming much more added sugar in processed foods, generally in the rapidly absorbed form of fructose.

That's an important clarification because our brains need sugar every day to function. Brain cells require two times the energy needed by all the other cells in the body; roughly 10% of our total daily energy requirements. This energy is derived from glucose (blood sugar), the gasoline of our brains. Sugar is not the brain's enemy—added sugar is.

Research indicates that a diet high in added sugar reduces the production of a brain chemical known as brain-derived neurotrophic factor (BDNF). Without BDNF, our brains can't form new memories and we can't learn (or remember) much of anything. Levels of BDNF are particularly low in people with an impaired glucose metabolism—diabetics and pre-diabetics—and as the amount of BDNF decreases, sugar metabolism worsens.

In other words, chronically eating added sugar reduces BDNF, and then the lowered levels of the brain chemical begin contributing to insulin resistance, which leads to type 2 diabetes and metabolic syndrome, which eventually leads to a host of other health problems. Once that happens, your brain and body are in a destructive cycle that's difficult if not impossible to reverse.

Research has also linked low BDNF levels to depression and dementia. It's possible that low BDNF may turn out to be the smoking gun in these and other diseases, like Alzheimer's, that tend to appear in clusters in epidemiological studies. More research is being conducted on this subject, but what seems clear in any case is that a reduced level of BDNF is bad news for our brains, and chronic sugar consumption is one of the worst inhibitory culprits.

Other studies have focused on sugar’s role in over-eating. We intuitively know that sugar and obesity are linked (since sugar is full of calories), but the exact reason why eating sugar-laden foods seems to make us want to eat more hasn’t been well understood until recently.

New research has shown that chronic consumption of added sugar dulls the brain’s mechanism for telling you to stop eating. It does so by reducing activity in the brain’s anorexigenic oxytocin system, which is responsible for throwing up the red “full” flag that prevents you from gorging. When oxytocin cells in the brain are blunted by over-consumption of sugar, the flag doesn’t work correctly and you start asking for seconds and thirds, and seeking out snacks at midnight.

What these and other studies strongly suggest is that most of us are seriously damaging ourselves with processed foods high in added sugar, and the damage begins with our brains. Seen in this light, chronic added-sugar consumption is no less a problem than smoking or alcoholism. And the hard truth is that we may have only begun to see the effects of what the endless sugar avalanche is doing to us.

Myth: Eating too much sugar causes diabetes.
Fact: No, it does not. Type 1 diabetes is caused by genetics and unknown factors that trigger the onset of the disease; type 2 diabetes is caused by genetics and lifestyle factors. Being overweight does increase your risk for developing type 2 diabetes, and a diet high in calories, whether from sugar or from fat, can contribute to weight gain. If you have a history of diabetes in your family, eating a healthy meal plan and regular exercise are recommended to manage your weight.

(in other words, lack of exercise, genetics and obesity cause diabetes, not eating sugar. I am not sure if you meant to imply this about sugar in the article, but your one paragraph can be interpreted that way, and in turn, is helping to spread a falsehood about diabetes. It is sort of like poking your arm. If you don't have a cut, it won't harm you. But if you do have a cut, then it can damage and hurt you. The cut in this analogy being diabetes and the poking being sugar)

A couple of things:
First, the connection between consumption of refined sugar (and that doesn't only mean straight sugar, but also processed carbohydrates) and BDNF levels is relatively new research and I'm not surprised the "official" definition doesn't make reference to it, yet.

While I agree that simply eating sugar doesn't cause diabetes, I think it's a huge mistake to not point to the obvious source of most of the average American's source of added sugar -- processed foods, be they in a grocery store, fast food or elsewhere -- and also added calories, and ignore the extremely strong correlation between this sort of diet and the onset of Type 2 diabetes. It's not even debatable. Our country is on the brink of a Type 2 epidemic and it's largely due to diet and inactivity.

Of course, lobbyists for the high fructose corn syrup industry want us to believe otherwise.

I think that's a great point and way of saying it David. If I might add (and feel free to correct). That when it comes to regulating BDNF levels, chronic and acute stress are the kings at doing this, which while yes can come in the form of improper diets, but another point to consider is that these dietary factors can also make any and all other stresses MORE stressful. They compound each other (or can be interchanged).

The comment above is thinking in terms of direct "cause-effect" (hence she says "genes" cause it) and many of these new ways of thinking of interactions are more complex and layered and most importantly about PROGRAMMING. For example "Early Life Programming" can prenatally impact such energy regulation factors and is shown in studies to be associated with Type 1 Diabetes as well (I would assume along with predisposing genetics and impacts that tweek those genetics). Hence why we speak of correlations instead of "the cause", our genetics put us on a projectory path, diet/exposures can either directly or indirectly (by creating greater vulnerabilities) create stress (which is a challenge to resources and an adaptation to 'improve' or protect) or make us vulnerable to being overly programmed by stressors (such as pathogens).

DIET
I would say I agree wholeheartedly it's largely due to diet, but in a more complicated way than what we think. Because yes, in this respect overly processed (HFCS and artificial transfats), lack of traditionally preserved foods which would be fermented instead of chlorinated (microbiota), and farming practices that lead to imbalanced fatty acid compositions (DHA, ALA, CLA, n-3 deficient balances) and pesticide exposures... all combine and interact in ways that can lead to immune responses, inflammation, cytokine production, and a multitude of regulation factors like BDNF getting down/up regulated in attempts to correct itself. Leading to compensatory maladaptation and degradation of systems basically over-worked, under-paid and desperately trying to compensate. As it might be described.

EXERCISE
As far as inactivity being a "culprit" I would say it may be collateral damage (from lack of energy, from the tweeked out energy-regulation factors), but it STILL is one of our BEST ways to re-tweek that programming (BDNF especially), basically it's a great way to expose ourselves to a controlled stress that we can recover from and become stronger, stress regulates stress. So it can be an incredibly important factor in creating solutions. Diet and Exercise... just not quite the way we think it (currently advised about it) and WAY beyond the "calorie in/out" oversimplified-to- the-point-of-being-misguiding advice. It may not be any where near as simple as it sounds and it may take a "whole systems" approach, both individually and corporations and communities and agricultural approaches to truly get to some solutions. The science seems pretty clear on these matters. So hopefully on a whole we are smart enough and motivated enough to get it done.

Oh boy did did you pick the absolutely worst site to copy and paste your misinformation from. The ADA have no interest in "curing" or preventing diabetes. There is too much money to be made in promulgation their brand of BS. Their first reaction is to reach for the drugs and their whole strategy revolves "living" with and "managing" your diabetes, not curing or *gasp* preventing in the first place. Invoking genetics is a weak cop-out. Type 1 is an auto-immune disease while type 2 is purely self-inflicted, or in the case of small children, child abuse. Regular exercise, while having many health benefits, will not prevent or cure diabesity. I suggest re-educating yourself as many of the things once taught are now recognized as false. There are many Doctors who have completely cured DMT2 through diet alone, and rest assured that diet does not include sugar and grains

On a personal note I have never during my adult life brought refined sugar into our home. On a professional note the macrobiotic approach; (as long as it is not applied in a macro neurotic :-) or macro robotic :-) way)… The macrobiotic approach offers all the alternatives with specific and enjoyable cooking styles to enjoy sweetness within one's day-to-day diet as well as wonderfully tasty desserts when and if desired.

It's puzzling to me why it is not embraced for what it offers: it is a what and how to do methodology for approaching dynamic health in a balanced, healthy and delicious way.

Excess focus on what not to do and what we may have been doing incorrectly or blindly often leads to more guilt/ineptitude/denial/avoidance and so on. The what and how to enjoy our daily food needs to become the primary focus.

The main trouble I face with reading an article like this is that it, like almost every other one on diet, comes close yet narrowly misses addressing the fundamental problem with the human diet. While discussing too much sugar, the author briefly mentions the role of grains. True, we eat too much sugar. We also eat way to many grains, i.e., carbohydrates.

The human digestive system developed over a million years on a diet low in carbs, yet we've accepted as "normal" a diet rich in carbs -- grains and sugars in particular -- because our ancestors discovered about 10,000 years ago that they could tame wild plants to keep their bellies full. Once our body chemistry has taken in enough carbs for its normal evolutionary health, all those extra carbs (bread, rice, etc.) have to go somewhere. The most common complaint we hear is excess body fat. I hadn't put two and two together yet on what impact those carbs rushing through my body must be doing to my brain chemistry as well, and by extension my mental health, but I'd wager it's not good for me.

I've been seeing a therapist for about two years. That's why I visit this site. But one of the best things I've done for my mental health I learned off the couch: eat way fewer carbs, an eat more meat, eggs, and raw veggies. I feel physically better since then and would love to see some research on how carbohydrates affect the brain chemistry.

The main trouble I face with reading an article like this is that it, like almost every other one on diet, comes close yet narrowly misses addressing the fundamental problem with the human diet. While discussing too much sugar, the author briefly mentions the role of grains. True, we eat too much sugar. We also eat way to many grains, i.e., carbohydrates.

The human digestive system developed over a million years on a diet low in carbs, yet we've accepted as "normal" a diet rich in carbs -- grains and sugars in particular -- because our ancestors discovered about 10,000 years ago that they could tame wild plants to keep their bellies full. Once our body chemistry has taken in enough carbs for its normal evolutionary health, all those extra carbs (bread, rice, etc.) have to go somewhere. The most common complaint we hear is excess body fat. I hadn't put two and two together yet on what impact those carbs rushing through my body must be doing to my brain chemistry as well, and by extension my mental health, but I'd wager it's not good for me.

I've been seeing a therapist for about two years. That's why I visit this site. But one of the best things I've done for my mental health I learned off the couch: eat way fewer carbs, an eat more meat, eggs, and raw veggies. I feel physically better since then and would love to see some research on how carbohydrates affect the brain chemistry.

I'm sorry but you are wrong about carbs in general. maybe you were eating processed carbs which are bad; the type of carbs matter. Fruits and veggies are the best foods for humans. the sugar in fruit converts straight to energy..You get all the protein and vitamins you need from these two food groups..plus whole grains and nuts. The human body has all the enzymes to digest carbs starting in our mouths and our colons are long like other herbivorous animals such as apes. On the other hand, lions, for example, have short colons, to quickly rid their bodies of undigested meat..thus lions do not get colon cancer and heart disease, humans who eat meat and dairy regularly do! Just b/c humans began to consume flesh somewhere in their evolution (probably out of extreme necessity) doesn't mean we were meant to eat it, or that we should and certainly not every day!

I am trying to break my sugar/processed food addiction. I am not overweight and very active. I exercise 7-10 hours/week. Can these harmful levels in the brain be corrected if you reduce your sugar intake. Much like a person's lungs can somewhat regenerate to a degree if the person quits smoking. I don't want to torture myself with no sugar if it will no improve this level! Just kidding, I know it will be best to stop, but I am curious about reversing the effects.

A few months ago I went on wellbutrin. Since then, I no longer crave sugar. I still eat it on occasion, but I don't crave it.

For most of my life, I have been a total sugar addict. If I didn't have treats in my house or in my office, I felt anxious and not good (its hard to believe I've never had a significant weight problem). Once I tried to give up sugar and made it for only 2 days. No matter how much I wanted to not eat chocolate several times a day or sweets, I couldn't do it. I was lucky I never had any significant health problems because of it. I swear, wellbutrin feels like a miracle in my life.

What journalists who write on psych-related subjects thought that picture was a good idea?

Who picked a picture of a faceless (dehumanizing), porny (objectifying) image of a sexy, thin (can't ever look at not-beautiful women, only beautiful women should exist and be looked at, beautiful women--the only kind of women--should be looked at like a porn object) woman (can't ever look at a non-woman in such an objectifying and dehumanizing way).

It feels like this picture is saying, "Ladies, don't you dare get fat, because that is not sexy" with the implication that "Imagine the horror of being fat! You wouldn't be sexy! Then you'd be worthless, because you're not sexy!". As someone who recognizes these non-verbal messages media pushes upon women, I should be immune to these messages, but I caught this because I had such an unusually urgent "OMG I DON'T WANT TO BE STUPID LIKE STUPID AMERICAN (WHITE) PEOPLE AND GET FAT" reaction before I even comprehended the third sentence. (Yes, I am non-white, which adds another interesting layer to how these media messages affect me.)

Haven't you people written about how media has a negative effect on ALL WOMEN and directly on a few men, and they make all of us think more sexist-ly??? Don't you guys know better than to contribute to that fucked-up message media? Were you hoping an image of a woman who's just give a blow job to a box of sugar cubes would increase traffic, and the affect this would have on women (and men's ideas about women) didn't matter as much as hits? Maybe you people just haven't written enough articles on The Beauty Myth, fat-anxiety and women.

Women are the group most responsible for women being seen as sex objects. Women endlessly, freely and enthusiastically present themselves in media (including porn) and everywhere else as sex objects. Take a look at women's magazines, for example, run by women.

Complain to your fellow women.

"Ladies, don't you dare get fat, because that is not sexy."

Actually, the vast majority of human beings don't think fat is sexy. That's biological, not a social construct.

I'm more concerned about how men are portrayed in the media, like a bunch of worthless buffoons, That subject gets zero attention, unlike your type of rant, which we've heard enough about for 100 lifetimes.

Hi, thanks for the comment.
You make an interesting point, though I think perhaps you are ignoring the flip side of your argument. If I'd chosen a picture of, say, an obese woman eating candy, I'd expect to receive a comment criticizing the choice, because (1) not only obese people have difficulty with sugar consumption, and (2) it would seem I'd be reinforcing a stereotype about fat people not being able to control themselves when it comes to food.

The photo effectively communicates the message that sugar has an addictive quality. That's really the point and I think it's conveyed well.

Frankly, we as a population are eating too much sugar. This has started to drastically affect the health of our population. In fact, if you were to take a trip to your local grocery store, you might be shocked at the sugar content of some food items that you took for granted. There is a brand new info-graphic which illustrates how sugar consumption is changing America. The rates of diabetes and obesity are going up, and some serious changes need to be made.

does anyone think that America's over-consumption of everything from lousy, cheap entertainment, celebrity gossip, and esp of rich, non-nutritious and horrible foods demonstrates that something is wrong with its psyche...that we are in misery...that we as a culture are in a steep decline, whereby we try to find something sweet to fill some void?
Of course there is the problem that we are a nation that always wants more and we consider more and bigger to be somehow better than less or smaller...to change these addictions it seems we need to overhaul the way most people think..but of course in the US if you tell someone to eat a piece of fruit instead of a twinkie, you are a communist! Look at all the flack the First Lady got for telling kids to eat veggies, ditch soda, and get off their lazy, fat asses!

I have to agree that one of the major issues here has to be our consumption of sugar. This is something that will only create mass problems as more people are diagnosed with other serious medical conditions like diabetes or heart disease. Equally alarming to me is the rise in childhood obesity that we have witnessed over the last few decades. The rate of obesity amongst this nation's youth has tripled since 1980! This is an issue that I think is worth discussing, and there is a great post available at: http://www.clinicaltrialsgps.com/news/childhood-obesity-a-growing-issue-in-america/

While I believe that as a culture we are certainly consuming too much sugar, I don't think that going sugar free is the answer. Moderation is the key here, and we just need to learn some more self-control.